The invention is related to a hydraulic unit for hydraulic control and regulation of apparatuses and more particularly to hydraulic brake pressure control units in anti-lock control systems or traction slip control systems for automotive vehicles.
Hydraulic units for the control or regulation of pressure agents have a wide range of application in industrial hydraulics. Particular importance has to be attributed to the use of hydraulic units for vehicle equipment, since the pressure agent streams provide high accuracy control even under extraordinary operating conditions.
Especially in regard to the integration of hydraulic units within the vehicle, additional active as well as passive measures have been considered, beyond strictly functional capabilities, which increase satisfaction as far as serviceability and low noise of the system are concerned.
Along these lines, mention has to be made of the arrangement as per the German patent application published without examination, No. 3,913,352 regarding a pressure pulsation damper within a hydraulic unit for brake systems with traction slip control. Depending on their properties of elastic deformation, these pulsation dampers absorb the sound emissions originating from the switching frequencies of the solenoid valves, so that the noise level which is felt to be annoying can be reduced. However, a disadvantage of this method results from the fact that elastic deformation of the pressure pulsation damper also necessarily leads to an undesired increase in the volume of pressure agent being taken in.